car shakes/vibrates when cold!
 

My 1981 240 shakes/vibrates excessively on cold start up. Its seems to decrease as it warms up. I know I have a bad motor mount, but that wouldn't explain why is lessens as the car warms up. I've also noticed after it warms up it does it less when in neutral or park. Suggestions??

Are your glow plugs working ok? I know on mine, when I have a glow plug go out in the winter, it vibrates a lot until that one cold cylinder starts firing ok.

That may be the old style glow plugs, no after glow, so it takes longer to warm up and smooth out.

Just replaced the glow plugs, so all of them are working. I noticed that my car does not have the "cigar hose"...at some point it was replaced w/ a regular fuel line. Could this be causing some of my vibration??

Probably not. My SD is the same way, but the cigar hose is fuel return, so it does not factor in to any fuel quality issues.

your motor mount is banging on the frame. when cold the motor is not as efficient, and it can focus on issues with fuel timing and injector spray problems. when was the last valve adjustment?
change your motor mount and see how much better it smooths out.